U.S. patent number 4,736,749 [Application Number 06/849,482] was granted by the patent office on 1988-04-12 for holder for medical use fixed by vacuum.
This patent grant is currently assigned to Astra-Tech Aktiebolag. Invention is credited to Stig Lundback.
United States Patent |
4,736,749 |
Lundback |
* April 12, 1988 |
Holder for medical use fixed by vacuum
Abstract
The invention relates to a holder for diagnostic and therapeutic
devices fixed by vacuum. Vacuum is supplied by a hose or tube (8),
in which one or several electrical conductors (7) for electrical
power supply or signal transmission are drawn. The holder comprises
a rigid backpiece (3), an intermediate elastomeric element (2), and
the diagnostic or therapeutic device (1). The intermediate element
(2) comprises a comparatively stiff sealing ring (9), which in a
working state is supported against the skin by a sealing lip (13)
and with its opposite side against the backpiece (3). The device
(1) is rigidly connected to the backpiece (3), but the sealing ring
of the intermediate element (2) is movable and, outwardly from the
backpiece, slightly resilient (via resilient means 17). When the
lip-side of the ring is not loaded and the ring thus pressed
outwardly, a vacuum valve is closed automatically through the
action of the intermediate component, and is re-opened when the
holder is pressed against the surface of the skin, whereupon the
holder is held firmly by suction.
Inventors: |
Lundback; Stig (Vaxholm,
SE) |
Assignee: |
Astra-Tech Aktiebolag
(Stockholm, SE)
|
[*] Notice: |
The portion of the term of this patent
subsequent to March 3, 2004 has been disclaimed. |
Family
ID: |
20359991 |
Appl.
No.: |
06/849,482 |
Filed: |
April 4, 1986 |
Foreign Application Priority Data
|
|
|
|
|
Apr 26, 1985 [SE] |
|
|
8502048 |
|
Current U.S.
Class: |
600/387;
607/149 |
Current CPC
Class: |
A61B
5/252 (20210101); A61B 7/04 (20130101); A61B
5/145 (20130101) |
Current International
Class: |
A61B
5/00 (20060101); A61B 5/0408 (20060101); A61B
7/00 (20060101); A61B 7/04 (20060101); A61B
005/04 () |
Field of
Search: |
;128/643,639-640,641,802-803 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1108820 |
|
Jun 1961 |
|
DE |
|
0639524 |
|
Feb 1979 |
|
SU |
|
Primary Examiner: Kamm; William E.
Assistant Examiner: Sykes; Angela D.
Attorney, Agent or Firm: Brumbaugh, Graves, Donohue &
Raymond
Claims
I claim:
1. A holder for diagnostic or therapeutic devices, for attachment
to the skin by the action of vacuum provided through a hose from a
vacuum source, and which comprises a diagnostic or therapeutic
arrangement (1), which is adapted to be connected to a measuring
instrument or an electrical power source (via 7) or both, and which
holder is adapted to be attached with a front side (4) engaging a
skin surface, and which comprises a rigid backpiece (3), to which
is attached the diagnostic or therapeutic arrangement (1) and a
sealing means (2), which surrounds said arrangement (1) and
comprises a sealing ring (9), circumferentially arranged around
said arrangement (1) and ending in a sealing lip (13), which
sealing ring (9) in a working state is adapted to abut against said
skin surface such that a volume connected to the vacuum source is
delimited by said skin surface and the sealing means, characterized
in that said arrangement (1) and the sealing lip (13) are movably
arranged with respect to each other under action of a resilient
force (via 17), which urges said arrangement (1) and a plane
defined by said sealing lip (13) away from each other, from a
working state (FIG. 3) to an idle state (FIG. 2), which movement
activates valve means for closing the supply vacuum to said volume
under vacuum, in that said arrangement (1), in both a working state
and an idle state, remains stationary relative to the backpiece
(3), and in that the sealing lip (13) is situated on a movable ring
(9), which is supported against the backpiece (3) in said working
state.
2. A holder according to claim 1, characterized in that both the
diagnostic or therapeutic arrangement (1) and the sealing means (2)
are components separate from each other and from the backpiece (3)
and are detachably connected to each other and to the backpiece
(3), whereby they may be removed from the backpiece and replaced by
like components.
3. A holder according to claim 2, characterized in that the sealing
means (2) comprises an elastomeric element (2) in a single piece,
which includes said sealing ring (9) incorporating the sealing lip
(13), in that the sealing ring on the part thereof remote from the
sealing lip includes a diaphragm disk with a central hole (18),
through which a stem part of the arrangement (1) is adapted to
pass, and in that the backpiece (3) is provided with holding means
(6) for that stem part (5).
4. A holder according to claim 3, characterized in that the means
for detachably holding the arrangement (1) to the backpiece
includes a snap fastener device.
5. A holder according to claim 3, and further characterized in that
the elastomeric element includes resilient means (17) compressible
in the working state into resilient engagement with the backpiece
and thereupon biasing the element away from the backpiece, in that
a first seal-forming means (15) forms a seal between the
elastomeric element and the backpiece, in that at least one opening
(11) through the elastomeric element within the seal of the first
seal-forming means is adapted to communicate a vacuum from the
source through the elastomeric element and in that said valve means
includes second seal-forming means (14) forming a seal between the
elastomeric element and the diagnostic or therapeutic arrangement
(1) when the resilient means (17) is in an uncompressed state,
whereby communication between a vacuum from the vacuum source and
the atmosphere external of the elastomeric element and the
arrangement is prevented in the idle state, said seal formed by the
second seal-forming means being broken when the sealing ring (9) is
moved toward the backpiece againsnt the bias of the resilient means
(17) in the working state, whereby vacuum is communicated to said
volume.
6. A holder according to claim 5, and further characterized in that
the resilient means (17) is a flange (17) extending
circumferentially of and outwardly from the elastomeric element,
the flange (17) being adapted to form a seal with a sealing lip
portion (16) on the backpiece (3) in the working state, the flange
being outwardly of the second seal-forming means (14), relative to
the opening (11), and wherein the elastomeric element has at least
one aperture (12) for communication of a vacuum in the working
state to a region of the backpiece bounded by the first and second
seal-forming means (15), whereby in the working state a force due
to the applied vacuum urges the backpiece (3) toward said surface
against the bias of the resilient means (17), which force retains
the holder attached to said surface with the arrangement in
engagement therewith.
7. A holder according to claim 1 and further characterized in that
the arrangement (1) has a frontal surface (4) adapted to engage the
skin surface in the working position and in that said front surface
is spaced-apart from the plane of the sealing lip (13) in a
direction toward the backpiece (3) when the holder is in the
working position.
8. A holder according to claim 7, characterized in that the frontal
surface (4) of the arrangement (1) is concave.
Description
BACKGROUND OF THE INVENTION
The invention relates to a holder for the attachment of diagnostic
and therapeutic devices to the skin at a certain predetermined site
of the human body.
Diagnostic and therapeutic devices intended to be attached to the
human body for a longer period than a few seconds are normally kept
in place by adhesive tape, by fixation with rubber bands or in a
similar way. For ECG-electrodes, fixation arrangements of an
essentially different kind have been described where fixation is
achieved with the aid of vacuum.
Said known arrangements for fixation display various drawbacks. The
method of attachment by adhesive tape is simple but does not
provide for the easy displacement of the device to another site of
the skin, in case it had not been put in the right place from the
beginning. Moreover, adhesive tape may cause inconvenience when
removed from areas with hair growth, may fall off through the
effect of transpiration, or may, in the case of uncautious handling
during application, fasten in places not considered for
application. With said fixation arrangements, it is moreover not
easy to bring into skin contact diagnostic and therapeutic devices
in a way that guarantees a constant force over time to be exerted
by the device onto the skin. Keeping the force of attachment
constant is important in, e.g., receiving electrical or acoustic
signals through the skin.
An ECG-electrode integrated arrangement for attachment displaying
the characteristics of the preamble of claim 1, which is thus
considered to be fastened by vacuum provided through a tube, and
which has a valve in closed position when the electrode is not
being attached opening automatically when it is applied, and
closing automatically when the electrode falls off, is known by the
Austrian patent specification No. 248608.
According to an embodiment described there, a spring-biassed
electrode plate with the aid of an elastic diaphragm is coupled to
a surrounding sealing ring. When the electrode plate is pressed
against the skin of a patient, a valve opens and vacuum is applied
to a cavity extending around the electrode, delimited by the
sealing ring.
Unfortunately, it has been found that the electrode plate abuting
against the skin becomes swiveling and axially movable in relation
to the sealing ring, resulting in inferior skin attachment and in a
varying contact between the skin and the electrode when there is
movement.
A holder integrated with an ECG-electrode, which is held in
position by means of vacuum and which has a surrounding sealing
ring which is relatively rigidly connected to a centrally located
electrode plate, is known from the U.S. Pat. No. 4,248,243. With
this electrode, however, suction cannot be applied through a tube
from a central vacuum source, since it lacks the self-closing valve
of the Austrian patent, which valve cannot be combined with the
rigid design. In addition to that, the arrangement described in the
US patent specification is highly disturbing since it emits a
whizzing noise arising in the ejector suction element.
SUMMARY OF THE INVENTION
An object of the invention is to provide a holder for attaching
various diagnostic or therapeutic devices to the skin that is easy
to attach, remains firmly in place, is easy to detach from the skin
and can be readily moved from one site to another. In particular, a
holder, according to the invention, comprises a rigid backpiece, to
which the diagnostic or therapeutic arrangement is attached, and a
seal element joined to the backpiece and surrounding the diagnostic
or therapeutic arrangement. The seal element comprises a sealing
ring at the perimeter that ends in a sealing lip that is engageable
with the skin. In a working state of the holder, the vacuum is
communicated to a region under the seal element within the sealing
lip. A deformable portion of the seal element allows movement of
the sealing ring, which movement opens a valve in the form of a rib
on the seal element that engages the therapeutic arrangement,
thereby allowing the vacuum connection to the seal element that
holds the holder securely against the skin. In an inactive state, a
resilient force applied to the seal element urges it away from the
backpiece such that the aforementioned valve closes. The opening of
the valve occurs automatically when the holder is pressed against
the skin, thereby moving the seal element against the resilient
force.
Diagnostic devices intended to be attached to the skin by means of
the present vacuum-fixed holder are, for example, electrodes for
electroencephalography (ECG), electrodes for electromyography
(EMG), sensors for skin temperature, humidity, and pH, biosensors
and other sensors for indirect or direct measurement of blood
gases, intramuscular sensor probes for, e.g., measurement of local
peripheral circulation by laser-Doppler techniques, microphones for
the registration of heart sounds, optical conductors for
observation of the skin, etc.
Therapeutic devices intended to be attached to the skin by means of
the present vacuum-fixed holder are, e.g., electrodes for
electrical stimulation of muscles, defibrillators, injectors for
intramuscular administration of pharmaceuticals, electrodes for
hyperthermal treatment, devices for percutaneous administration of
pharmaceuticals, etc.
In accordance with an advantageous aspect, the invention may be
realized in embodiments of partially disposable sort or with easily
exchangeable parts which are sterilizable.
The diagnostic or therapeutic arrangement may be rigidly or
removably connected to the vacuum-fixed holder. If removably
connected, the connection may advantageously be made according to
the press-stud connection principle, commonly called a "snap
fastener".
DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to an
exemplifying but not limiting embodiment thereof. In this
context,
FIG. 1 shows an exploded sectional view of a holder consisting of
three components.
FIG. 2 shows a sectional view of a holder in idle position and
FIG. 3 shows a sectional view of a holder in active position that
is, with the holder attached to the skin.
FIG. 4 is a sectional view of an exemplary diagnostic
arrangement.
DESCRIPTION OF PREFERRED EMBODIMENT
The various parts of the embodiment are best seen from FIG. 1. The
diagnostic or therapeutic arrangement has a preferentially flat
surface or a surface which is slightly concave with respect to the
skin. Its outer form is determined by the cooperation with the
other components of the holder described here. The diagnostically
or therapeutically operative part 30 of the arrangement 1 is
preferentially arranged at or near surface 4. The operative part 30
is connected to a recorder or to an electrical power source not
shown in FIGS. 1-3. Arrangement 1 on the side opposite to surface 4
is provided with a stem 5, forming the male part of a press-stud
connector that can be fastened in the female part 6 of the
connector in a backpiece 3, which female part thereby penetrates a
hole 18 in an intermediate element 2, which, i.a., comprises
sealing ring 9. It is a resilient press-stud connector of a type in
common use. Although not shown in FIGS. 1-3, the male and female
parts of the press-stud connector comprise a number of isolated
electrical and other contacts necessary for the transmission of
signals or power. The backpiece 3 may be advantageously made of
non-conducting plastics, eventually provided with some sort of
electrical shielding not shown here. To backpiece 3, there is
connected a vacuum hose or tube communicating with a vacuum pump or
a reservoir, in which the shielded electrical conductors are drawn
to the female part 6. When the press-stud connection is made via
5,6, the diagnostic or therapeutic arrangement 1 is thus rigidly
connected to the backpiece and, via the lead or bundle of
conductors 7, communicates with measuring equipment or a power
source of known type. The vacuum tube 8 is connected to a cavity in
backpiece 3 and, circumferentially to the press-stud connector part
6, there are provided a number of holes 20.
When the three parts in FIG. 1 are assembled, the configuration
shown in FIG. 2 is obtained. For the sake of clarity, only FIG. 1
has been provided with reference numbers, but a comparison is easy
to make anyway. In the example shown, parts 1 and 2 are
rotationally symmetric which simplifies manufacture but is not
absolutely necessary.
Part 2, which is made from silicone rubber or a similar material,
has a relatively rigid ring portion 9 with a circumferential
sealing lip 13, which in use is sealing against the skin. To start
with, the function in an idle state will be described.
It is obvious that the relatively flat central portion of
intermediate element 2 provided with hole 18 will abut against the
sealing lip 15 in backpiece 3. The front side of the central
portion via circumferentially arranged holes 11 communicates with
the rear side of intermediate element 2, on which there is arranged
another sealing lip 14. This lip will abut against the rear side of
the diagnostic or therapeutic arrangement 1, and both lip 14 and 15
will seal off a volume around the central portion of part 1 being
put under vacuum, whereby a certain bending of the central portion
of intermediate element 2 occurs to which also contributes that
flange 17 on the intermediate part 2 is elastically abuting against
lip 16 on backpiece 3. With the configuration in FIG. 2,
notwithstanding unsignificant leakage, only said volume around the
central part of arrangement 1 will be put under vacuum.
When the electrode, being in a configuration according to FIG. 2,
is attached to a skin surface, the following will occur. When the
circumferential lip is pressed against the skin, the force will
affect flange 17 via the relatively rigid ring 9, which is
resiliently deformed, whereby the central part of intermediate
element 2 is more excessively deformed and lip 14 eases away from
the rear side of arrangement 1. The space between the skin and the
intermediate element 2 is placed in communication with the vacuum
source, and since the intermediate element 2 is provided with holes
12 in its peripheral part, all spaces will be placed under vacuum,
the sealing lips 13 and 16 therewith sealing between the backpiece
3 and the skin. The configuration illustrated in FIG. 3 is thereby
obtained.
It will be clear from FIG. 3 that the backpiece 3 and the ring 9
now function as an interlocking composite assembly. Although the
ring 9 is urged outwardly, away from the backpiece 3 by an elastic
deformation force acting through the flange 17, this force is quite
insignificant in comparison with the pneumatic forces. The vacuum
used need not reach more than 0.1 kg/cm.sup.2. The air pressure
then exerts against the skin a force which corresponds
substantially to the force exerted by the surface embraced by lip
13. This force is counter-acted by the resistance normally offered
by the skin, the greater part of which resistance is exerted on the
under-surface 4 of arrangement 1, thereby to achieve particularly
good contact. Due to the deformation of the skin, there is also
obtained a certain shape-conforming effect which prevents slipping.
A break force applied via hose 8 will cause the skin to accompany
the movement until deformation is too great and the lip 13 is no
longer able to provide a seal, whereupon the electrode will fall
off, and the resilient flange returns to the position shown in FIG.
2, with the valve seal once again in effect.
Thus, in order to obtain good functioning, the surface 4 of
arrangement 1 in the position shown in FIG. 3 must be inwardly
drawn relative to the lip 13 on the ring 9. With a diameter of 30
mm for the lip, the surface is suitably inwardly drawn to a depth
of 3-4 mm.
The described embodiment has been shown to function extremely well.
For example, arrangement 1 comprising a micro electret microphone
has made possible the objective recording of heart sounds.
Recording of heart sounds with simultaneous recording of ECG
provides valuable information in various types of heart defects.
The position of the microphone may be easily changed until the
optimal position for the registration of the respective heart sound
has been found. A microphone amplifier can be integrated in
arrangement 1 in order to further improve signal quality.
An arrangement of known type as such for the registration of
acoustic signals is shown in FIG. 4. The sound is transferred from
the skin to the diaphragm 21 and, from there, to the microphone 22.
Conductors 23 and 24 connect the microphone with contacts 25 and 26
at the male part 5 of the press-stud connector. The female
connector part not shown here has been arranged to fit contacts 25
and 26 and has two conductors isolated from each other, which
together constitute conductor bundle 7 in the vacuum tube 8 and
lead to the recording instrument not shown here.
Arrangement 1 can be easily adapted to comprise other diagnostic
and therapeutic arrangements mentioned before.
The good fixation of the holder provides for the recording of heart
sounds, temperature, measurement of blood gases, etc., even in the
case of physical activity, for example in examinations under
physical exercise. The presence of dense body hair does not prevent
the holder from remaining firmly seated. Because of the negative
pressure being small, the holer may remain attached for a long
period of time without suction marks appearing on the skin, except
for a slight red ring where lip 13 abuts the skin.
The press-stud connection between the diagnostic or therapeutic
element 1 and the backpiece 3 makes the former easily exchangeable.
This makes possible that new or sterilized used parts can be
rapidly placed on the holder, which may be used for the next
patient. The elastomer element 2 can be made of sterilizable
material and be used repeatedly. The invention thereby is
exceptionally practical and hygienic. When it is used under
conditions with increased transpiration, it may be appropriate to
mount in the holder some moisture-absorbing material, e.g. a disk
of fibrous material, which can be inserted between the elastomer
element and the backpiece, and which may be discarded after
use.
* * * * *